The victims have been identified as Sachin, a student of Class X, Pravin of class XII and Pradeep, who is pursuing a course from ITI.
Superintendent of Police Rajiv Malhotra said that the victims were sitting at their common shop in Kookra village, when four persons threw acid on them.
They have been admitted in a hospital, he added.
Police said that the motive behind the attack could be personal enmity.
A case has been registered against after a complain was filed against them.